Method for improving acoustic model, computer for improving acoustic model and computer program thereof

Abstract

Embodiments include methods and systems for improving an acoustic model. Aspects include acquiring a first standard deviation value by calculating standard deviation of a feature from first training data and acquiring a second standard deviation value by calculating standard deviation of a feature from second training data acquired in a different environment from an environment of the first training data. Aspects also include creating a feature adapted to an environment where the first training data is recorded, by multiplying the feature acquired from the second training data by a ratio obtained by dividing the first standard deviation value by the second standard deviation value. Aspects further include reconstructing an acoustic model constructed using training data acquired in the same environment as the environment of the first training data using the feature adapted to the environment where the first training data is recorded.

What is claimed is: 
     
       1. A method for improving an acoustic model, comprising:
 acquiring, by a computer, a first standard deviation value by calculating standard deviation of a first feature from a first training data acquired in first environment; 
 acquiring, by the computer, a second standard deviation value by calculating standard deviation of a second feature from second training data acquired in a second environment; 
 calculating, by the computer, a modified first feature, by multiplying the second feature acquired from the second training data by a ratio obtained by dividing the first standard deviation value by the second standard deviation value; 
 reconstructing, by the computer, an acoustic model constructed using training data acquired in the first environment, using the modified first feature; 
 acquiring speech data for speech recognition; and 
 performing speech recognition on the speech data using the reconstructed acoustic model. 
 
     
     
       2. The method according to  claim 1 , wherein environment includes the recording hardware and software used to acquire training data, and wherein the feature is a ceptsrum, and wherein the first training data is speech data recorded under the same conditions as conditions of an operation environment, and the second training data is speech data recorded under different conditions from conditions of the operation environment.